.si vs .ai: Which Domain Should an AI Startup Choose?
Slovenia’s .si has become shorthand for “super intelligence.” Before you build on it, here is how it compares with .ai, the extension the AI industry already runs on.
The short answer
For most AI startups, .ai should be the primary address and .si the strategic second. The .ai extension is established, treated as global by search engines and familiar to buyers. The .si extension is new to this role, inexpensive to register and matches the term the US government now uses. Owning both covers you whichever way the vocabulary goes.
Side by side
| .si | .ai | |
|---|---|---|
| Country | Slovenia | Anguilla |
| Who can register | Anyone, any country, no local presence | Anyone, no local presence |
| Names registered | About 259,000 (Oct 2026) | About 1.5 million (Oct 2026) |
| How Google treats it | A signal for Slovenia | Generic, like .com |
| Disputes | ARDS, the registry’s own process | UDRP, with WIPO as provider |
| Registration term | 1 to 5 years | Up to 10 years at most registrars |
| Relative cost | A fraction of .ai | Several times .si |
When .ai should be your main address
- You sell globally and depend on search. Google lists .ai among the country codes it treats as generic. A site on .si can still rank, but it starts with a signal pointing at Slovenia.
- Your buyers already expect it. Years of AI launches have trained customers and investors to read .ai as “an AI company.”
- You may need to value or finance the name. .ai has a deep record of public sales, from Voice.ai at $1.5 million to Chat.ai at $1.2 million, which makes appraisal far easier.
When .si earns its place
- Brand protection. Impersonation started fast: since September 19, Netcraft counted 119 new .si domains containing “pay” and 37 containing “bank.” Holding your own .si keeps it out of the wrong hands.
- Government-facing work. If federal agencies are your customers, a name that matches their new vocabulary is an easy fit for SI-branded products or programs.
- Early-stage investment. The zone is still far smaller than .ai, and interest predates the announcement: recursive.si sold for $20,000 in May 2026.
Three things to check before registering a .si
- Use a contact email you will control long term. The registry requires a working address that the holder controls, and it can delete a domain if those obligations aren’t met.
- Expect resale noise. About half of the .si names registered through one large US registrar were listed for resale within days. Quality varies widely.
- Know the dispute process. .si disputes go through ARDS rather than UDRP. A name that copies someone else’s trademark can be transferred or deleted.
For individuals, the .si registry publishes only the holder’s contact email in WHOIS, which keeps names, addresses and phone numbers out of public view.
The setup we recommend
Run the company on the .ai name. Hold the matching .si and point it at the main site with a permanent (301) redirect. You get the search strength and familiarity of .ai, plus the defensive and future value of .si, with one website to maintain. It is the same setup this site uses: every name in our collection points to ziq.ai.